1. Field
An aspect of the present disclosure relates generally to an electronic device and, more particularly, to a three-dimensional semiconductor device and a manufacturing method thereof.
2. Description of the Related Art
Nonvolatile memory devices are memory devices which retain stored data even when a power supply is turned off. Recently, as improvements of the degree of integration of two-dimensional nonvolatile memory devices in which memory cells are formed in a single layer over a silicon substrate have reached a limit, there has been proposed a three-dimensional nonvolatile memory device in which memory cells are three-dimensionally arranged. A three-dimensional (3-D) nonvolatile memory device includes vertical channel layers protruding from a substrate, and a plurality of memory cells are stacked along each vertical channel layer.